The present invention relates generally to corrosion resistant martensitic stainless steel alloys, and, more particularly, to a case hardenable stainless steel alloy suitable for use in high temperature bearing applications and like carburized components such as, for example, cams, shafts, bolts, gears and the like for use at high temperatures in corrosive atmospheres. The alloy of the invention, when case carburized and heat treated, provides an excellent combination of high surface hardness with hot hardness capabilities and core toughness.
Alloys used in such applications as bearings and gears require a high surface hardness for metal-to-metal wear resistance while maintaining a core exhibiting good fracture toughness, ductility and impact toughness for use in such applications as, for example, engines and transmissions. Currently used alloys include AMS 6278 (M50-NiL), as well as the alloys disclosed in U.S. Pat. Nos. 2,876,152; 4,004,952; 4,157,258 and 5,002,729. To date, such alloys provide these capabilities but fail to provide the additional properties of corrosion resistance and high hardness when used in high temperature applications. There is an increasing demand for alloys of this type at the present time which is expected to increase further in the future.